%0 Journal Article %T Combustion and Emission Characteristics of Variable Compression Ignition Engine Fueled with Jatropha curcas Ethyl Ester Blends at Different Compression Ratio %A Rajneesh Kumar %A Anoop Kumar Dixit %J Journal of Renewable Energy %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/872923 %X Engine performance and emission characteristics of unmodified biodiesel fueled diesel engines are highly influenced by their ignition and combustion behavior. In this study, emission and combustion characteristics were studied when the engine operated using the different blends (B10, B20, B30, and B40) and normal diesel fuel (B0) as well as when varying the compression ratio from 16.5£¿:£¿1 to 17.5£¿:£¿1 to 18.5£¿:£¿1. The change of compression ratio from 16.5£¿:£¿1 to 18.5£¿:£¿1 resulted in 27.1%, 27.29%, 26.38%, 28.48%, and 34.68% increase in cylinder pressure for the blends B0, B10, B20, B30, and B40, respectively, at 75% of rated load conditions. Higher peak heat release rate increased by 23.19%, 14.03%, 26.32%, 21.87%, and 25.53% for the blends B0, B10, B20, B30, and B40, respectively, at 75% of rated load conditions, when compression ratio was increased from16.5£¿:£¿1 to 18.5£¿:£¿1. The delay period decreased by 21.26%, CO emission reduced by 14.28%, and emission increased by 22.84% for B40 blends at 75% of rated load conditions, when compression ratio was increased from 16.5£¿:£¿1 to 18.5£¿:£¿1. It is concluded that Jatropha oil ester can be used as fuel in diesel engine by blending it with diesel fuel. 1. Introduction The world is presently confronted with the twin crises of fossil fuel depletion and environmental degradation. Indiscriminate extraction and lavish consumption of fossil fuels have led to reduction in underground-based carbon resources. The search for alternative fuels, which promise a harmonious correlation with sustainable development, energy conservation, efficiency, and environmental preservation, has become very important today. Intensive research is going on throughout the globe for a suitable diesel substitute. In this race among different alternatives, vegetable oils have attained primary place as some of their physical, chemical, and combustion related properties are nearly similar to those of diesel fuel. A lot of research work has been carried out to use vegetable oil in its neat form. Since India is net importer of vegetable oils, edible oils cannot be used for substitution of diesel fuel. So, major concentration has been focused on nonedible oils as the fuel alternative to diesel fuel. Many efforts have been made by several researchers to use nonedible oil as an alternative fuel in CI engine. Nonedible oil from the plant seeds is the most promising alternative fuel for CI engine, because it is renewable, environment friendly, nontoxic, biodegradable, also has no sulphur and aromatics, and has favorable heating value and higher cetane %U http://www.hindawi.com/journals/jre/2014/872923/